Fire retardant polymeric additives

ABSTRACT

A fire retardant additive comprising particles of a polymer of:

RELATED APPLICATIONS

This is a division of application Ser. No. 397,515 filed Sept. 17, 1973now U.S. Pat. No. 3,948,842, granted Apr. 6, 1976 which, in turn, is acontinuation-in-part of application Ser. No. 49,204, filed June 23,1970, now U.S. Pat. No. 3,725,509, granted Apr. 3, 1973, and the nowabandoned application Ser. No. 160,905, filed July 8, 1971 the latterapplication, in turn, being a continuation-in-part of the formerapplication. The respective disclosures of both of said applications areincorporated herein by reference.

BACKGROUND OF THE INVENTION

Polymers of halogen-containing ethylenically unsaturated monomers, suchas the vinyl or vinylidene halides, are often prepared as aqueouslatices or emulsions in which form they may be conveniently used ascoatings, adhesives, paint bases, binders for non-woven fabrics,coatings for woven fabrics including fabrics prepared from natural,synthetic, mineral or glass fibers and in various other types ofapplications. In many instances, particularly where they are beingconsidered for use in building interiors or in uses repairing theirprolonged exposure to high temperatures, it is highly desirable andadvantageous that these latices should display enhanced fire or flameretardant properties and color stability so that they may be safelyemployed in place of more costly materials. Moreover, it is highlydesirable and advantageous that these latices when applied to flexiblesubstrates, should impart a desirably soft "hand" to said substrates.

Prior attempts to provide fire retardant, film-forming vinyl orvinylidene halide polymer latices have involved the preparation ofvarious polymeric compositions including copolymer latices of vinylhalides and alkyl acrylates, copolymer latices of vinyl halides andvinylidene chloride and polyvinyl halide latices containing anextraneously added phosphate ester plasticizer. Other attempts haveinvolved the use of interpolymers of bis(β-chloroethyl) vinylphosphonate with lower alkyl acrylates or methacrylates and acrylic ormethacrylic nitriles. These interpolymers could additionally optionallyinclude vinyl halides or vinylidene halides. Still other attempts haveinvolved interpolymerization of vinylidene halide monomers withcarboxylic acid monomers and N-alkylol acrylamide monomers. These latterinterpolymers could optionally include other polymerizable comonomerssuch as esters of acrylic acid or methacrylic acid, vinyl acetate,acrylonitrile, methacrylonitrile, acrylamide or methacrylamide, styreneor bis(β-haloalkyl) vinyl phosphonates. However, despite the many andvaried attempts to obtain a completely satisfactory polymeric latex,none of the above-described approaches has proven to be completelysatisfactory as the resultant products are found, in many cases, to belacking in either sufficient fire retardancy, color stability,mechanical stability, ultraviolet stability, softness of the polymers orthe products are subject to the gradual loss of their extraneously addedphosphate plasticizers.

Accordingly, it is an object of this invention to provide novel, fireretardant halogen-containing vinyl polymer additives which may be usedin a variety of coating, binding, and laminating applications and whichare characterized by their essentially complete freedom from the variousdisadvantageous properties heretofore associated with this type ofproduct.

It is another object of this invention to provide a novel class ofpolymers in the form of aqueous emulsions or latices which areparticularly useful, as additives, for preparing fire retardant, polymercompositions which are in the form of aqueous solutions, suspensions or,most preferably, emulsions.

It is a further object of this invention to provide solid polymeric fireretardant additives or blends by drying or coagulating or co-coagulatingthe polymer emulsions or latices of this invention by themselves or asblends with other polymeric emulsions or latices. The solid polymericadditives of the present invention can also be blended with ordinarilyflammable solid polymers to give flame retardant polymeric blends.

It is still another object of the present invention to provide a novelclass of polymers in the form of aqueous emulsions or latices which areparticularly useful as binders for non-woven fabrics and coating forwoven fabrics prepared from natural, synthetic, mineral, glass fibers ormixtures thereof.

Various other objects and advantages of this invention will be apparentfrom the disclosure thereof which follows hereinafter.

TECHNICAL DISCLOSURE OF THE INVENTION

In its broadest aspect, this invention resides in the discovery that awide variety of polymers, particularly polymers in the form of solids,aqueous solutions, suspensions or, most preferably, emulsions, as wellas a wide variety of fiber and fabric substrates may be rendered fireretardant by the incorporation therein or the application thereto of thenovel polymeric additives of the present invention. These additivescomprise polymers of: (1) one or more halogen-containing vinyl monomerswith (2) one or more phosphorus-containing vinyl monomers as hereinafterdefined, and (3) one or more additional comonomers as hereinafterfurther defined, these polymers being in the form of solid particles orparticles in an aqueous emulsion or latex. More particularly, it has nowbeen discovered that the use of aqueous emulsion or latex polymers orthe coagula or dried particles thereof formed from one or morehalogen-containing vinyl monomers with one or more bis(hydrocarbyl)vinyl phosphonates and one or more additional comonomers as hereinafterdefined, impart to the resulting composition or material a high degreeof fire retardance and excellent color stability without adverselyaffecting any of the significant physical properties thereof. Inaddition, it has been found that the polymers of the present inventionimpart a desirably soft hand to materials upon which they are coated orwithin which they are impregnated. Moreover, it is truly surprising andadvantageous to find that polymer blends resulting from the process ofthis invention, particularly those blends which are in the form of anaqueous emulsion or latex system, display an outstanding degree ofcompatibility since, as is well known to those skilled in the art,physical blends of two or more polymers are almost always characterizedby their inherently poor compatibility.

The novel polymers suitable for use as fire retardant additives inaccordance with the process of this invention comprise polymers of:

1. at least one halogen-containing, alpha, beta-ethylenicallyunsaturated monomer, i.e., vinyl monomers including vinyl halides suchas, for example, vinyl chloride, vinyl fluoride and vinyl bromide,halogenated C₁ -C₁₂ alkyl acrylates and methacrylates such as, forexample, methyl alpha-chloroacrylate and methyl alpha-bromoacrylate;vinylidene halides such as, for example, vinylidene chloride, vinylidenebromide, vinylidene chlorobromide and vinylidene fluoride;halo-substituted nitriles of ethylenically unsaturated carboxylic acidssuch as, for example, alpha-chloroacrylonitrile; and the chlorinatedstyrenes such as, for example alpha-chlorostyrene, o-chlorostyrene,m-chlorostyrene, p-chlorostyrene, and 2,4-dichlorostyrene;

2. at least one bis(hydrocarbyl)vinylphosphonate having the structure:##STR3## wherein X is selected from the group consisting of hydrogen,halogen, cyano, aryl such as phenyl, C₁ -C₁₈ alkyl and ##STR4## whereinR and R' are hydrocarbyl and substituted hydrocarbyl groups consistingessentially of hydrogen and carbon and containing up to about 18 carbonatoms inclusive with the proviso that R and R' may be the same,different or conjoint, i.e., R and R' may combine to form one singleradical; and

3. at least one comonomer including alpha olefins such as ethylene,propylene and butylene; vinyl esters of carboxylic acids, such as vinylacetate, vinyl butyrate and vinyl stearate; and C₁ -C₂₀ alkyl esters ofacrylic acid and methacrylic acid such as methyl methacrylate, methylacrylate, ethyl acrylate, n-butyl acrylate, sec.-butyl acrylate,tert.-butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate and thelike; ethylenically unsaturated dicarboxylic acids, their anhydrides andtheir C₁ -C₂₀ mono- and dialkyl esters such as aconitic acid, fumaricacid, maleic acid, itaconic acid, citraconic acid, maleic anhydride,dibutyl fumarate and monoethyl maleate; amides of ethylenicallyunsaturated carboxylic acids such as acrylamide and methacrylamide andtheir N-methylol and diacetone derivatives such as N-methylolacrylamide, N-methylol methacrylamide and diacetone acrylamide; vinylaryl compounds such as styrene and alpha-methyl styrene; C₁ -C₂₀ alkylvinyl ethers such as methyl vinyl ether, ethyl vinyl ether and stearylvinyl ether; dienes such as isoprene and butadiene; and glycidyl estersof acrylic and methacrylic acid such as glycidyl acrylate and glycidylmethacrylate. The preferred comonomers are the C₁ -C₂₀ alkyl esters ofacrylic and methacrylic acid especially the lower (C₄ -C₈) alkylacrylates.

It is considered preferably to include the N-methylol and diacetonederivatives of amides of ethylenically unsaturated carboxylic acids suchas, for example, N-methylol acrylamide or diacetone acrylamide whichserve to provide the resulting polymer with cross-linking sites.

The use, in this disclosure, of the expression "hydrocarbyl" and"substituted hydrocarbyl groups" in the definition of the suitablebis(hydrocarbyl)vinylphosphonates given hereinabove refers to theradicals obtained upon the removal of a hydrogen from a hydrocarbon orsubstituted hydrocarbon group which may be either an aliphatic oraromatic group. These hydrocarbyl groups may be substituted with anynon-interferring groups, i.e., with any group which does not interferewith the polymerization of the bis-(hydrocarbyl)vinylphosphonate. Suchsubstituent groups include, for example, chloro, bromo, fluoro, nitro,hydroxy, sulfone, ethoxy, methoxy, nitrile, ether, ester and keto groupsand the like.

Illustrative of the aliphatic and aromatic groups as are represented byR and R' in the structure of the bis-(hydrocarbyl)vinylphosphonate givenhereinabove are alkyl groups, such as methyl, ethyl, propyl, butyl,pentyl, hexyl, nonyl, and the like; alkenyl groups such as pentenyl andhexenyl groups and all of their respective isomers; cycloalkyl groups,such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like;cycloalkenyl groups such as cyclohexenyl and the like; typical arylgroups include phenyl, benzyl, phenethyl, tolyl, naphthyl and the like.

Representative of the above-defined bis(hydrocarbyl)vinylphosphonatesare:

Bis(beta-chloroethyl)vinylphosphonate;

Bis(beta-chloropropyl)vinylphosphonate;

Bis(beta-chloroethyl) 1-methylvinylphosphonate;

Bis(beta-chloroethyl) 1-cyanovinylphosphonate;

Bis(beta-chloroethyl) 1-chlorovinylphosphonate;

Bis(beta-chloroethyl) 1-phenylvinylphosphonate;

Dimethyl vinylphosphonate;

Diethyl vinylphosphonate;

Bis(omega-chlorobutyl)vinylphosphonate;

Di-n-butyl vinylphosphonate;

Di-isobutyl vinylphosphonate;

Bis(2-chloroisopropyl) 1-methylvinylphosphonate;

Diphenyl vinylphosphonate; and

Bis(2,3-dibromopropyl)vinylphosphonate

From the above group of bis(hydrocarbyl)vinylphosphonate monomers, it ispreferred to employ bis(beta-chloroethyl)vinylphosphonate in preparingthe novel aqueous emulsion polymers of this invention since the lattermonomer is a commercially available material and lower in cost than anyof the other bis(hydrocarbyl)vinylphosphonates.

Although either a vinyl halide or a vinylidene halide monomer can besuitably employed as the halogen-containing ethylenically unsaturatedmonomer in the aqueous emulsion polymers of the present invention, it isconsidered preferable to employ vinylidene halide monomers since thevinylidene halide monomers when incorporated into polymers of thepresent invention impart a soft "hand" to substrates upon which they arecoated or within which they are impregnated. The preferred thirdcomonomer for use in the polymers of the present invention is an alkylacrylate, preferably, the C₄ -C₈ alkyl acrylates such as n-butylacrylate and 2-ethylhexyl acrylate. It has been found that inclusion inthe polymer of an alkyl acrylate aids in imparting good color stabilityand softness to the resulting polymer. It is to be noted, at this point,that the use of the term "polymer" in this disclosure is meant to applyto polymers derived from three or more distinct monomeric species.

In addition to the above described bis(hydrocarbyl)vinylphosphonates, itis also possible to prepare aqueous emulsion polymers useful as flameretardant additives by employing: (1) mono (alkyl) acidvinylphosphonates such as, for example, mono(ethyl) hydrogenvinylphosphonate, mono(butyl) hydrogen vinylphosphonate,mono(octyl)hydrogen vinylphosphonate; mono(beta-chloroethyl)hydrogenvinylphosphonate, mono (omega-chlorooctyl)hydrogen vinylphosphonate; (2)mono(cycloalkyl) and mono(aryl)hydrogen vinylphosphonates such as, forexample, mono(cyclohexyl)hydrogen vinylphosphonate, mono(phenyl)hydrogen vinylphosphonate, mono(benzyl)hydrogen vinylphosphonate; (3)bis(cycloalkyl) and bis(aryl)vinylphosphonates, such as, for example,bis(cyclohexyl)vinylphosphonate and bis(benzyl) vinylphosphonates; and,(4) bis(alkyl), bis(cycloalkyl), and bis(aryl) allylphosphonates, suchas, for example bis(beta-chloroethyl)allylphosphonate, bis(cyclohexyl)allylphosphonate and bis(benzyl)allylphosphonate as well as mixtures ofany two or more of the above described phosphonate monomers.

The polymers of the present invention can be prepared by means of freeradical initiated emulsion polymerization techniques well known to thoseskilled in the art. In these procedures, the various monomers andcatalysts are emulsified, in water, by means of one or moresurface-active emulsifiers whereupon the polymerization reaction is theninitiated. Suitable water soluble, free radical initiating catalysts foruse in preparing the copolymer latices of this invention include sodium,potassium and ammonium persulfate and hydrogen peroxide or one may use aredox system such, for example, as a mixture of a persulfate with analkali metal bisulfite, thiosulfate or hydrosulfite. These catalystsshould be present in a concentration of from about 0.05 to 5.0%, byweight, of the total monomer charge. With respect to the emulsifier orsurfactant, it is possible to utilize one or more anionic, cationic, ornon-ionic emulsifiers such, for example, as the alkyl carboxylic acidsalts; the alkyl sulfate, sulfonate, phosphate, or sulfosuccinate salts;the alkyl aryl polyether alcohols, and the alkyl aryl polyether sulfatesalts. The selected emulsifier or emulsifiers should be present ineffective concentrations of from about 0.03 to 6.0%, by weight, of thetotal monomer charge. In addition, a protective colloid such aspolyvinyl alcohol, polyvinyl pyrrolidone, methyl cellulose or gelatincan also, if desired, be present in the recipe in an effectiveconcentration of from about 0.03 to 6.0%, by weight, of the totalmonomer charge. Alternatively, the protective colloid may be introducedinto the polymer latex subsequent to its preparation. When post-added inthis manner, the protective colloid should be present in a concentrationof from about 0.03 to 6.0%, by weight, of the total resin solids. In anyevent, the presence of the protective colloid serves to enhance themechanical stability of the emulsion.

The actual polymerization reaction will ordinarily be conducted at atemperature of from about 0° to 100° C. for a period of from about 1 to24 hours, depending upon such factors as the particular monomer,catalysts, surfactants and polymerization apparatus that is beingutilized. The latices resulting from this polymerization process willordinarily have a resin solids content of from about 5 to 70%, byweight, wherein the particles have a diameter which ranges in size fromabout 0.03 to 3.0 microns.

With respect to proportions, these aqueous emulsion or latex polymerparticles may contain from about 1 to 89% by weight, of one or more ofthe above described bis(hydrocarbyl) vinyl phosphonates, from about 10to 98% by weight of one or more of the above-describedhalogen-containing ethylenically unsaturated monomers and from about 1to 45% by weight of one or more of the above-described third comonomers.Optimum results, as flame retardant additives imparting good colorstability to a wide variety of polymeric, natural, glass or mineralsubstrates and adapted to impart good "hand" to said substrates areobtained by use of polymers in accordance with the present inventioncontaining from about 10 to 75% by weight of one or more of thebis(hydrocarbyl)vinylphosphonates, from about 20 to 85% by weight of oneor more of the above-described halogen-containing ethylenicallyunsaturated monomers and from about 5 to 35% by weight of one or more ofthe above-described third comonomers. Most preferred, is a polymercontaining about 45-55% by weight ofbis(beta-chloroethyl)vinylphosphonate, 25-35% by weight of vinylidenechloride, 14-20% by weight of n-butyl acrylate and 1-5% by weight ofN-methylol acrylamide. n-Butyl acrylate can be replaced, withoutaffecting the properties of the latex polymer, by 2-ethyl hexylacrylate. When 2-ethylhexyl acrylate is used, the most preferredcomposition contains 65-75% by weight of vinylidene chloride, 12-22% byweight of bis(beta-chloroethyl)vinylphosphonate, 5- 13% by weight of2-ethylhexyl acrylate and 1-5% by weight of N-methylol acrylamide.

With respect to the above-described proportions for the composition ofthe aqueous emulsion or latex polymers of this invention, it has beenfound that it becomes increasingly more difficult to attain goodpolymerization conversion rates as attempts are made to increase theamount of the bis(hydrocarbyl)vinylphosphonate in the resulting polymersubstantially above a concentration of about 60% by weight. On the otherhand, the use of these polymer emulsions as flame retardant additivesbecomes progressively more inefficient when they contain substantiallyless than about 5% by weight of one or morebis(hydrocarbyl)vinylphosphonates, since a rather high concentration ofthe polymer will then be required in order to attain flame retardancy.The use of such high concentrations of these polymer additives may, inturn, result in some deterioration in the inherent physical propertiesof the thus modified composition or material.

Specific aqueous emulsion polymer compositions which have been found toprovide particularly good results as additives for the preparation offire retardant compositions are:

1. a terpolymer of 81 parts by weight of vinylidene chloride, 5 parts byweight of n-butyl acrylate and 14 parts by weight ofbis(beta-chloroethyl)vinylphosphonate;

2. a terpolymer containing 15 parts by weight of di-n-butyl vinylphosphonate, 20 parts by weight of di-n-octyl fumarate and 65 parts byweight of vinylidene chloride;

3. a terpolymer containing 15 parts by weightbis(beta-chloroethyl)vinylphosphonate, 5 parts by weight propylene and80 parts by weight vinylidene chloride;

4. a terpolymer containing 25 parts by weight vinylidene bromide, 65parts by weight bis(beta-chloroethyl)vinyl phosphonate and 10 partsvinyl acetate; and

5. a polymer containing 50 parts by weight vinyl chloride, 35 parts byweight bis(2-chloroisopropyl) 1-methyl vinyl phosphonate, 15 parts byweight stearyl vinyl ether and 5 parts by weight N-methylol acrylamide.

It is important, with respect to this disclosure, to distinguish betweenthe processes of suspension and emulsion polymerization. Thus,suspension polymerization refers to a method of polymerization wherebyone or more monomers is dispersed in a suspension medium which is anon-solvent for both the monomer and the resulting polymer. Generally,water is utilized for this purpose and a monomer soluble polymerizationinitiator is thereupon introduced. Polymerization takes place within themonomer phase containing the polymerization initiator. The use of thesuspending medium assists in the dissipation of the heat of reaction andthe polymerization reaction is therefore easier to control. Suspensionpolymerization is generally accomplished by dispersing the monomer inthe suspending medium either by constant agitation or by the use of asuspending agent or both. Various suspending agents are known in theart. These known suspending agents include gelatin, hydroxy methylcellulose, hydroxy ethyl cellulose, hydroxy propyl cellulose, carboxymethyl cellulose, talc, clay, polyvinyl alcohol and the like.

By contrast, emulsion polymerization involves a process whereby one ormore monomers are emulsified in the form of droplets within a continuousphase which should be inert with respect to both the emulsified monomersand the resulting polymer. Water is generally selected as the continuousphase. Emulsification of the monomers is facilitated by the use of oneor more emulsification agents which tend to reduce the interfacialtension between the dispersed and continuous phases. Typical emulsifiersinclude common soaps, salts of long-chain carboxylic and sulfonic acids,alkylated aromatic sulfonic acids and salts of long-chain amines.

A water soluble initiator is employed and it is believed that thepolymer chains originate in the continuous, aqueous phase and thencontinue their growth in the dispersed monomer-polymer phase yieldingthe polymer product in a finely divided state which remains emulsifiedwithin the continuous, aqueous medium. Thus, an important distinctionbetween emulsion and suspension polymerization is that in the former,the monomer is either dispersed into droplets which are stabilized by anadsorbed layer of soap molecules or is solubilized in the soap micellewhich is present in aqueous soap solutions. As a result, stable polymeremulsions are readily obtained; whereas, in a suspension polymerization,the resulting polymer particles are of a relatively larger mass whichtend to more readily separate out from the suspension.

In all cases, the novel aqueous emulsion or latex polymers of thisinvention or the coagula or dried particles thereof have been found toprovide blends with ordinarily flammable polymers in either emulsion,latex or dry, solid form; the emulsion or latex polymers of theinvention also serve as binders for non-woven fabrics or coating forwoven fabrics which are characterized by their outstanding fireretardancy. As used in this disclosure, the term "fire retardant" or"flame retardent" is intended to refer to that particular property of amaterial which provides it with a degree of resistance to ignition andburning. Thus, a fire or flame retardant composition is one which has alow level of flammability and flame spread. This property may beconveniently evaluated by means of any of the standard flame retardancytests such, for example, as the ASTM test D-635.

As has been indicated, hereinabove, the aqueous emulsion or latexpolymers of this invention are particularly suitable for blending withordinarily flammable polymers which are in the form of aqueous systemssuch as solutions, suspensions, or, most preferably, emulsions. Theresulting aqueous blends, like the aqueous emulsion or latex polymers ofthe present invention per se, may then be used in any of the variouscoating, adhesive, binding, laminating and impregnating applicationsknown to those skilled in the art. Thus, these aqueous blends may becoated upon and/or absorbed by all types of substrates to which it isdesired to impart fire retardant properties. They may, therefore, beused as coatings, impregnants, fillers, laminates, and adhesives forsuch substrates as wood; paper; metals; non-woven fabrics and woventextiles based on either natural, synthetic, mineral or glass fibers orblends thereof, for example, woven and non-woven fabrics and textilesmade from fibers of cotton, wool, silk, polyester, nylon, rayon,asbestos, fiber glass and blends thereof; synthetic polymer films suchas those based upon polyolefins, regenerated cellulose, i.e.,cellophane, polyvinyl chloride, polyesters and the like; leather;natural and synthetic rubber; fiber-board; and synthetic plasticsprepared by means of either addition or condensation polymerizationtechniques.

Any desired polymeric material may be blended with the above-describedbis (hydrocarbyl) vinyl phosphonate polymer additives in order toprepare fire retardant compositions. If the polymeric material to bemodified is in the form of an aqueous solution, suspension or emulsion,the polymer latex of this invention can be used as such as the flameretardant additive. If, on the other hand, the polymeric material to bemodified is in the form of a solid or a solution in at least one organicsolvent, then the preferred form of the flame retardant additive is thesolid polymer coagulated from the polymer latex of the above-describedcomposition. Such polymeric materials include:

1. Polymers of vinyl chloride including polyvinyl chloride and therandom and graft copolymers of vinyl chloride with a minor proportion ofone or more of the abovedescribed group of vinyl monomers which areincluded as comonomers for use in preparing the aqueous emulsioncopolymers of this invention;

2. Polymers of the C₁ -C₈ alkyl acrylates and methacrylates includingtheir homopolymers and their copolymers with each other and with a minorproportion of such comonomers as the alpha-olefins, e.g. ethylene andpropylene; the vinyl esters of carboxylic acids, e.g. vinyl acetate;ethyleneically unsaturated monocarboxylic acids, e.g. acrylic andmethacrylic acids; ethylenically unsaturated dicarboxylic acids theiranhydrides and their C₁ -C₂₀ mono- and dialkyl esters, e.g. maleic acid,maleic anhydride, diethyl maleate and monobutyl acid maleate; vinylidenehalides, e.g. vinylidene chloride; C₁ -C₂₀ alkyl vinyl ethers, e.g.methyl vinyl ether; amides of ethylenically unsaturated monocarboxylicacids, e.g. acrylamide and the N-methylol and diacetone derivatives;vinyl aryl compounds, e.g. alphamethyl styrene and styrene; and,nitriles of alpha, beta-ethylenically unsaturated carboxylic acids, e.g.acrylonitrile and methacrylonitrile.

3. Polymers of nitriles of ethylenically unsaturated acids includingpolymethacrylonitrile, polyacrylonitrile and the copolymers ofmethacrylonitrile and acrylonitrile with a minor proportion of one ormore vinyl monomers such as the lower alkyl acrylates and methacrylates,styrene and alphamethyl styrene;

4. Acrylonitrile-butadiene-styrene resins, commonly referred to as "ABS"resins, which generally comprise either a mixture of a 60 to 80:40 to 20styrene:acrylonitrile copolymer with from about 10 to 40%, by weight, ofa 5 to 40:95 to 60 acrylonitrile-butadiene copolymer or a mixture of a60 to 80:40 to 20 styrene:acrylonitrile copolymer with from about 10 to40%, by weight, of a graft of the latter copolymer onto polybutadiene;

5. Poly(alpha-olefins) such as polypropylene and polyethylene andcopolymers of one or more alpha-olefins, such as ethylene or propylene,with a minor proportion of one or more ethylenically unsaturatedmonomers including 4-methyl pentene-1, butene-1, norbornene and itsderivatives; cyclopentadiene, cyclopentene, cyclobutene, vinyl acetate,the C₁ -C₁₂ alkyl acrylate and methacrylate esters, as well as blends ofthe homo and copolymers of alpha-olefins with other types ofthermoplastic polymers;

6. Polymers of styrene including polystyrene, poly(alpha-methyl styrene)and poly(tertiary butyl styrene) and copolymers of styrene, alpha-methylstyrene or tertiary butyl styrene with a minor proportion of one or moreethylenically unsaturated comonomers such, for example, as nitriles orethylenically unsaturated carboxylic acids including acrylonitrile andmethacrylonitrile; C₁ -C₁₂ alkyl esters of acrylic and methacrylic acidssuch, for example, as methyl methacrylate and 2-ethylhexyl acrylate;and, graft copolymers of styrene, tertiary butyl styrene or alpha-methylstyrene with polybutadiene and other hydrocarbon elastomers;

7. Cellulosic resins including cellulose esters and mixed esters such,for example, as cellulose nitrate, cellulose acetate-butyrate, celluloseacetate-propionate and cellulose ethers such, for example as ethylcellulose;

8. Polyamide resins, i.e., the resins made by the condensation of di- orpolyamines with di- or polybasic acids or by polymerization of lactamsor amino acids. Typical polyamides include nylon 4 which is made frompyrrolidone; nylon 6 obtained by polycondensation of caprolactam; nylon66 obtained by the condensation of hexamethylene diamine with adipicacid; nylon 610 obtained by the condensation of hexamethylenediaminewith sebacic acid; nylon 7 which is a polymer of ethyl aminoheptanoate;nylon 9 made from 9-aminononanoic acid; and, nylon 11 made from 11-aminoundecanoic acid;

9. Polyester resins, i.e., the resins produced by the condensation ofsaturated or unsaturated dibasic acids, such as terephthalic, maleic,fumaric, isophthalic, adipic and azelaic acids with dihydric alcoholssuch as ethylene glycol, propylene glycol, diethylene glycol anddipropylene glycol. Where the resin is made with an unsaturated acid, apolymerizable monomer such, for example, as styrene, vinyl toluene,diallyl phthalate, methyl methacrylate; chlorostyrene, alpha-methylstyrene, divinyl benzene or triallyl cyanurate is often included in thecomposition;

10. Polyurethane resins, i.e. the resins formed by the reaction betweena bi- or polyfunctional hydroxyl containing compound, such as apolyether or polyester, and a di- or polyisocyanurate such as toluenediisocyanate or diphenylmethane-4,4'-diisocyanate;

11. Polycarbonate resins, i.e., the resins derived from the reactionbetween a difunctional alcohol or phenol, such as bis-phenol A, andphosgene or an alkyl or aryl carbonate;

12. Polyacetal resins, i.e. the resins derived from the anionicpolymerization of formaldehyde to obtain a linear molecule of the type-O-CH₂ -O-CH₂ -O-CH₂ -;

13. Polyphenylene oxide resins made by the oxidative polymerization of2,6-dimethylphenol in the presence of a copper-amine-complex catalyst;

14. Polysulfone resins, i.e., the resins containing an SO₂ linkage asderived from the reaction of sulfur dioxide with olefins such as1-butene or, more preferably, by reaction of bis-phenol A with4,4'-dichlorodiphenyl sulfone;

15. The acrylate:styrene:acrylonitrile resins commonly referred to as"ASA" resins, which comprise copolymers containing a major proportion ofa C₂ -C₈ alkyl acrylate ester elastomer upon which is grafted about 65 -95%, by weight of the latter copolymer, of a 70 - 80:30 - 20styrene:acrylonitrile copolymer;

16. The methacrylate:butadiene:styrene resins, commonly referred to asthe "MBS" resins, which comprise a minor proportion of a methylmethacrylate:styrene:acrylonitrile terpolymer grafted and/or blendedwith either polybutadiene or a copolymer of butadiene and minorproportions of such comonomers as, for example, styrene andacrylonitrile;

17. Polymers of vinyl acetate including polyvinyl acetate and the randomand graft copolymers of vinyl chloride with a minor proportion of one ormore of the vinyl monomers which were listed as optional comonomers foruse in preparing the aqueous emulsion polymers of this invention; and,

18. Aminoplast resins made by the polycondensation of formaldehyde witha nitrogen containing compound such as urea or malamine; and

19. Phenolic resins made by the polycondensation of phenols withaldehydes such as formaldehyde, acetaldehyde or furfural aldehyde.

In effect, one may utilize any ordinarily flammable polymeric materialin preparing fire retardant polyblends with the novel polymer additivesof this invention. These ordinarily flammable polymeric materials may bethermoplastic polymers, i.e., polymers which can be softened by heat andwhich then regain their original properties on cooling. Also applicableare polymer systems comprising copolymers containing one or morecrosslinkable comonomers, i.e, monomers containing two or moredissimilar functional groups, such, for example, as N-methylolacrylamide, N-methylol methacrylamide, glycidyl acrylate and glycidylmethacrylate. Thus, the polymers containing one or more of thesecrosslinkable comonomers can be cured or crosslinked, by the use of heatand/or catalysts and are thereby converted into a form in which theywill no longer be thermoplastic but will, rather, be thermosetting,i.e., they will not dissolve in contact with a solvent or water.Ideally, the novel polymer additives of this invention would be blendedwith such crosslinkable copolymer systems prior to the time they undergothis curing or crosslinking operation.

The actual blending of the aqueous emulsion polymer additives of thisinvention with the selected polymeric materials i.e., with any one ormore of the above described polymers, may be accomplished by means ofany convenient procedure which will result in an intimate admixture ofthe additive within the polymeric mass. Thus, for example, an aqueousemulsion of latex containing the particles of the polymer additive maysimply be blended or otherwise admixed with a polymer which should,preferably, be in the form of an aqueous solution, latex or suspension.The resulting aqueous blend can be used as such or can be co-coagulatedto form a solid, polymeric blend. Or, if desired, the aqueous polymeremulsion of this invention can be coagulated by freezing or by additionof NaCl solution, methanol or the like to recover the polymer additivein solid particulate form. The polymer additive and another of thepolymer's described above may be admixed while each is in the form of asolid.

The blending operation may also be carried out by means of a procedurein which the polymer to be modified is itself polymerized while in thepresence of one of the previously polymerized aqueous emulsion polymeradditives of this invention. Alternatively, thebis(hydrocarbyl)vinyl-phosphonate-containing aqueous emulsion polymeradditive may be polymerized in a system which contains the previouslypolymerized polymer in an appropriate physical form, e.g. as an aqueoussolution, suspension or emulsion.

With respect to proportions, the amount ofbis(hydrocarbyl)vinylphosphonate-containing aqueous emulsion or latexpolymer which may be admixed with an ordinarily flammable polymer willdepend, primarily, upon such factors as the particular phosphonatepolymer and the polymer which is to be blended with one another, thedegree of fire retardancy desired in the resulting blend, the degree ofclarity, hardness and other specific physical properties which aresought as well as other technical and economic considerations known andunderstood by those skilled in the art. However, in order to attain acomposition which will be self-extinguishing, it is generally desirableto introduce an effective concentration of bis(alkyl)vinylphosphonateaqueous emulsion polymer solids which will be sufficient to provide theresulting blend with at least about 0.5%, by weight, of phosphorus andwith at least about 10%, by weight, of halogen, i.e., chlorine and/orbromine, derived from the halogen containing ethylenically unsaturatedmonomer and also, if possible, from thebis(hydrocarbyl)vinylphosphonate.

The fire retardant polymer compositions of this invention can beprepared so as to contain various optional additives which may includeplasticizers such as the alkyl esters of phthalic, adipic and sebacicacids such, for example, as dioctyl phthalate and ditridecyl phthalateand aryl phosphate esters such, for example, as triphenyl and tricresylphosphate, etc.; lubricants and mold release agents such as stearic acidor its metal salts, petroleum based waxes, mineral oils and theirhalogenated products, polyethylene waxes and their halogenated productetc.; and heat and light stabilizers such as barium, cadium, calcium,zinc soaps or phenates, basic lead compounds, organo-tin compounds, suchas dialkyl tin mercaptides and dialkyl tin maleates, thiolauricanhydride and n-butyl stannoic acid, epoxidized oils, alkyl diphenylphosphites, triaryl phosphites, phenyl salicylates, o-hydroxybenzophenones and benzotriazoles, etc. For a more complete listing ofplasticizers, lubricants, stabilizers and other functional additives,one may consult "Polyvinyl Chloride" by H. A. Sarvetnick published byVan Nostrand Reinhold Co., New York, N.Y., in 1969.

The compositions of this invention may also contain fillers, pigments,dyes, opacifying agents, decorative additives such as reflective metalfoils or flakes, and other imbedded solid objects such as fiber glass,textile fibers, asbestos, and the like, provided that they do notdetract from the flame retardancy of these products. In addition, thecompositions may contain other flame retardants such as antimonycompounds, zinc borate, aluminum hydrate, halogenated alkyl phosphatesor phosphonates, alkyl acid phosphates, or small concentrations ofphosphoric acid.

The novel fire retardant compositions of this invention, whethercomprising blends of any of the above described polymeric material withone or more of the novel fire retardant additives of this invention orwhether comprising the fire retardant additives of the presentinvention, per se, may be utilized in any of the coating, adhesive,impregnating laminating, binding and painting applications known tothose skilled in the art wherein it is desired to provide fireretardancy to the resulting end product. For example, these compositionsmay be used in such application as rug and carpet backing adhesives, asadhesives for fiber glass, as a backing coating for fabrics, as heatsealable binders for nonwoven fabrics, as flooring, coatings, as papercoatings, as paint bases and as adhesives for preparing laminatedstructures.

In addition to being used as fire retardant additives for thepreparation of fire retardant polymer blends with flammable polymersubstrates, the aqueous emulsion polymer additives of this invention maybe used, per se, in any of the various coating, painting adhesive,laminating, impregnating and binding applications known to those skilledin the art. Thus, they may be coated upon and/or adsorbed by all typesof substrates to which it is desired to impart fire retardantproperties. They may, therefore, be used as coatings, impregnants,fillers, laminants, and adhesives for such substrates as wood; paper;metals; non-woven fabrics and textiles based on either natural,synthetic, mineral or glass fibers or blends thereof; synthetic polymerfilms such as those based upon polyolefins, regenerated cellulose, i.e.,cellophane, polyvinyl chloride, polyesters and the like; leather,natural and synthetic rubber; fiberboard; and, synthetic plasticsprepared by means of either addition or condensation polymerizationtechniques.

The following examples will further illustrate the various embodimentsof this invention. In these examples, all parts and percentages givenare by weight unless otherwise noted.

In the following examples, the polymers obtained are evaluated for colorstability, fire retardant (FR) properties and hand as follows:

1. Color Stability

Film samples cast from various latices are placed in a forced air ovenset at 60° C. for 8 hours. The samples are then rated as possessing goodcolor stability if they remained clear and colorless and as possessingpoor color stability if they turned yellow to brown.

2. FR Properties

Film samples cast from various latices are held in a vertical positionand ignited for 2 seconds with a Bunsen burner. The burner is thenremoved. Samples which self-extinguished and would not continue to burnwithin 5 seconds after the burner was removed were noted as possessinggood FR properties. Samples which continued to burn for more than 5seconds after removal of the burner or burn the entire length within 5seconds were noted as possessing poor FR properties.

3. Hand

Hand is evaluated by flexing films cast from various latices. A hardfilm can be readily distinguished from a soft film upon flexing of thefilm.

EXAMPLE 1

Into a 32 ounce polymerization vessel, there are charged 120 partsbis(beta-chloroethyl)vinylphosphonate, hereinafter referred to as"bis-beta", 90 parts n-butyl acrylate, 90 parts vinylidene chloride, 110parts deionized water, 60 parts of a 10% aqueous solution of sodiumlauryl sulfate and 120 parts of a 5% aqueous solution of polyvinylalcohol. The pH of the resulting mixture is adjusted to a value of about8 by addition of 3.3 parts of 58% aqueous solution of ammoniumhydroxide, whereupon 110 parts of a 5% aqueous solution of ammoniumpersulfate is added to the mixture. The air space above the liquid levelin the reactor is purged with nitrogen and the vessel is sealed. Thevessel is shaken to form a stable emulsion. Polymerization is effectedat a temperature of 55° C. over a period of 12 hours with apolymerization vessel being continuously subjected to a tumblingagitation. A stable latex of good color stability is obtained. When thelatex is poured onto a Petri dish and dried, a film exhibiting a softhand is recovered. When ignited with a Bunsen burner for two seconds andthe burner then removed, the film does not support combustion andtherefore exhibits good FR properties.

A portion of the emulsion prepared above is blended with an aqueousemulsion containing 46% of polybutyl acrylate polymer particles whosefilms are ordinarily flammable. The concentration of the bis-betapolymer solids in the blend is 20% based on the polybutyl acrylatesolids. A film having a dry thickness of 5 mils is cast from the polymerblend and is found to exhibit good fire retardance.

EXAMPLES 2-8

The following polymers are prepared as set forth below:

    ______________________________________                                        (2)   vinylidene chloride     65 parts                                              di-n-butyl vinyl phosphonate                                                                          15 parts                                              di-n-octyl fumarate     20 parts                                        (3)   vinylidene chloride     80 parts                                              bis(beta-chloroethyl)vinylphosphonate                                                                 15 parts                                              propylene               5 parts                                         (4)   vinylidene bromide      25 parts                                              bis(beta-chloroethyl)vinylphosphonate                                                                 65 parts                                              vinyl acetate           10 parts                                        (5)   bis(beta-chloroethyl)vinylphosphonate                                                                 50 parts                                              vinylidene chloride     30 parts                                              2-ethylhexyl acrylate   20 parts                                        (6)   vinylidene chloride     68 parts                                              bis(beta-chloroethyl)vinylphosphonate                                                                 19 parts                                              2-ethylhexyl acrylate   9 parts                                               N-methylol acrylamide   4 parts                                         (7)   vinyl chloride          50 parts                                              bis(2-chloroisopropyl)1-methylvinyl-                                          phosphonate             35 parts                                              stearyl vinyl ether     15 parts                                              N-methylol acrylamide   5 parts                                         (8)   bis(beta-chloroethyl)vinylphosphonate                                                                 47.6 parts                                            vinylidene chloride     28.6 parts                                            n-butyl acrylate        19.0 parts                                            N-methylol acrylamide   4.8 parts                                       ______________________________________                                    

Each of the above monomer mixtures is added to 100 parts of deionizedwater containing 6 parts of sodium lauryl sulfate and 3 parts ofammonium persulfate in a suitable reaction vessel. The air space abovethe liquid level is purged with nitrogen and the vessel is sealed. Thevessel is gently stirred to form a stable emulsion and then maintainedat 60° C for 16 hours. In each instance, a stable latex of good colorstability is obtained. When the latices are poured onto a Petri dish anddried, soft films are recovered. When ignited with a Bunsen burner for 2seconds and the burner is removed, the films do not support combustion.

EXAMPLES 9-10

These examples compare polymers obtained in accordance with the presentinvention containing bis-beta, n-butyl acrylate and vinylidene chloridewith prior art polymers containing bis-beta, n-butyl acrylate,vinylidene chloride and acrylic acid (U.S. Pat. No. 3,682,871) andpolymers containing bis-beta, n-butyl acrylate, vinylidene chloride andacrylonitrile (U.S. Pat. No. 3,489,706).

The polymers are prepared in the manner set forth in Examples 2-8. TableI below, summarizes the reactants, conditions and results obtained.

                                      TABLE I                                     __________________________________________________________________________                      Comparative            Comparative                                            Example                Example                              COMPOSITION PARTS U.S. 3,682,871                                                                         Example 9                                                                            Example 10                                                                           U.S. 3,489,706                       __________________________________________________________________________    Bis-Beta          12       12     25     25                                   n-Butyl Acrylate  35       35     59     59                                   Vinylidene Chloride                                                                             50       50     50     50                                   Acrylonitrile     --       --     --     12                                   Acrylic Acid      10       --     --     --                                   N-Methylol Acrylamide                                                                           1.5      1.5    1.5    1.5                                  Time Hrs.         12       12     12     12                                   Temp. ° C  55       55     60     60                                   Deionized H.sub.2 O                                                                             25       25     100    100                                  Sodium Lauryl Sulfate (10% Soln)                                                                35       35     100    100                                  Ammonium Persulfate (5% Soln)                                                                   40       40     --     --                                   NaCO.sub.3 /NaHCO.sub.3                                                                         --       --     1/1    1/1                                  Ammonium Persulfate                                                                             --       --     0.4    0.4                                                    FILM EVALUATION                                             Color Stability   Poor     Good   Good   Poor                                 FR Properties     Good     Good   Good   Good                                 "HAND"            Hard     Soft   Soft   Hard                                 __________________________________________________________________________

It can be clearly seen that the polymers of the present invention aresuperior to those of the prior art both with respect to color stabilityand especially hand.

EXAMPLES 11-12

Examples 11 and 12 illustrate that a soft hand can be imparted to thepolymers of the present invention by substituting vinylidene chloridefor vinyl chloride in the polymer. Surprisingly, as shown in thecomparative examples, copolymers of bis beta and either vinyl chlorideor vinylidene chloride are characterized by a hard hand and poor colorstability; whereas, a bis-beta copolymer with n-butyl acrylate, whilepossessing good color stability and soft hand exhibits poor FRproperties.

The polymers are prepared in the manner set forth in Example 1. Table IIbelow summarizes the reactants, conditions and results obtained.

                                      TABLE II                                    __________________________________________________________________________    COMPOSITION                                                                    PARTS       Example 11                                                                          Example 12                                                                            Comparative Examples                               __________________________________________________________________________    Bis-Beta     120   120    120                                                                              120   120                                        n-Butyl Acrylate                                                                            90    90    -- --    180                                        Vinylidene                                                                    Chloride      90   --     180                                                                              --    --                                         Vinyl                                                                         Chloride     --     90    --  90   --                                         Time Hrs      12    12     12                                                                               12    12                                        Temp. ° C                                                                            55    55     55                                                                               55    55                                        Deionized H.sub.2 O                                                                        110   110    110                                                                              110   110                                        Sodium Lauryl Sulfate                                                         (10% Soln)    60    60     60                                                                               60    60                                        Ammonium Persulfate                                                           (5% Soln)    110   110    110                                                                              110   110                                        Polyvinyl Alcohol                                                             (5% Soln)    120   120    120                                                                              120   120                                        Conc NH.sub.4 OH                                                                           3.3   3.3    3.3                                                                              3.3   3.3                                                     FILM EVALUATION                                                  Color Stability                                                                            Good  Good   Poor                                                                             Poor  Good                                       FR Properties                                                                              Good  Good   Good                                                                             Good  Poor                                       "HAND"       Soft  Hard   Hard                                                                             Hard  Soft                                       __________________________________________________________________________

EXAMPLES 13-14

Examples 13 and 14 as compared with the comparative example illustratethat even among similar terpolymers, the particular combination ofcomonomers in the terpolymers of the present invention provideterpolymers of significantly better properties as compared to suchsimilar terpolymers.

The polymers are prepared in the manner set forth in Example 1. TableIII below summarizes the reactants, conditions and results obtained.

                  TABLE III                                                       ______________________________________                                                        Example  Example  Comparative                                 Composition Parts                                                                             13       14       Example                                     ______________________________________                                        Bis-Beta        120      120      120                                         n-Butyl Acrylate                                                                              90       90       --                                          Vinylidene                                                                    Chloride        90       --       90                                          Vinyl                                                                         Chloride        --       90       90                                          Time Hrs        12       12       12                                          Temp. ° C                                                                              55       55       55                                          Deionized H.sub.2 O                                                                           110      110      110                                         Sodium Lauryl Sulfate                                                                         60       60       60                                          (10% Soln)                                                                    Ammonium Persulfate                                                                           110      110      110                                         (5% Soln)                                                                     Polyvinyl Alcohol                                                                             120      120      120                                         (5% Soln)                                                                     Conc NH.sub.4 OH                                                                              3.3      3.3      3.3                                                       FILM EVALUATION                                                 Color Stability Good     Good     Poor                                        FR Properties   Good     Good     Good                                        "HAND"          Soft     Hard     Hard                                        ______________________________________                                    

EXAMPLES 15-17

Examples 15 to 17 illustrate that terpolymers exhibiting excellentproperties can be obtained with a wide variety of crosslinking agents.

The polymers are prepared in the manner set forth in Example 1 and inExamples 2-8. The reactants, conditions and results obtained aresummarized in Table IV.

                  TABLE IV                                                        ______________________________________                                        COMPOSITION                                                                    PARTS         Example 15                                                                              Example 16                                                                              Example 17                                 ______________________________________                                        Bis-Beta       25        120       120                                        n-Butyl Acrylate                                                                             59        90        90                                         Vinylidene     50        90        90                                         Chloride                                                                      Glycidyl       --        10        --                                         methacrylate                                                                  Di Acetone     --        --        10                                         Acrylamide                                                                    N-Methylol     1.5       --        --                                         Acrylamide                                                                    Time Hrs       12        12        12                                         Temp. ° C                                                                             60        55        55                                         Deionized H.sub.2 O                                                                          100       110       110                                        Sodium Lauryl Sulfate                                                                        100       60        60                                         (10% Soln)                                                                    Ammonium Persulfate                                                                          --        110       110                                        (5% Soln)                                                                     NaCO.sub.3 /NaHCO.sub.3                                                                      1/1       --        --                                         Ammonium Persulfate                                                                          0.4       --        --                                         Polyvinyl Alcohol                                                                            --        120       120                                        (5% Soln)                                                                     Conc NH.sub.4 OH                                                                             --        3.3       3.3                                                     FILM EVALUATION                                                  Color Stability                                                                              Good      Good      Good                                       FR Properties  Good      Good      Good                                       "HAND"         Soft      Soft      Soft                                       ______________________________________                                    

EXAMPLE 18

Two pad baths were prepared by mixing the following ingredients:

    ______________________________________                                                          A        B                                                  ______________________________________                                        A polymer latex prepared according                                            to Ex. 1 (adjusted to 50% solids)                                                                 120 parts                                                 A commercial all-acrylic latex                                                (50% solids)                   120 parts                                      Water                50 parts   50 parts                                      ______________________________________                                    

Two pieces of a 11/2 oz non-woven fabric consisting of cotton fiberslaminated on a rayon scrim were used in this test. One was immersed inbath A and the other in bath B. They were squeeze-dried and then heatedat 170° C. for 8 minutes. The dried fabrics were cut into 2×12 inch teststrips for flammability testing after conditioning for 24 hours at 78°F. and 80% relative humidity.

The samples were kept at a vertical position. A 2-second contact with aBunsen burner flame ignited the samples. Upon removal of the flame, thesamples treated with bath B burned the entire length of 12 inches andthe samples treated with bath A left a char length of about 6 inches.This is, the flame propagated to half the length of the test samples andextinguished by itself.

EXAMPLE 19

A commercial stocking of nylon 6,6(poly-hexamethylene adipamide) was cutinto 2 pieces and treated with bath A and bath B separately as describedin Example 18. Flammability tests showed that samples treated with bathA were self-extinguishing upon removal of flame and samples treated withbath B burned the entire length.

EXAMPLE 20

A commercial garment of 65/35 polyester/rayon blend was cut into 2pieces and treated with bath A and bath B separately, as described inExample 18. Flammability tests showed that samples treated with bath Awere self-extinguishing and samples treated with bath B burned theentire length.

EXAMPLE 21

Two pad baths were prepared by mixing the following ingredients:

    ______________________________________                                                           C       D                                                  ______________________________________                                        A polymer latex prepared according                                            to Example 6 (adjusted to 48% solids)                                                              --        100 parts                                      A commercial all-acrylic latex                                                (48% solids)         200 parts 100 parts                                      Aqueous pigment dispersion                                                    (Inmont 26-9750 blue)                                                                               10 parts  10 parts                                      10% glass coupling agent solution                                             (10% hydrolyzed Dow-Corning Z-6040)                                                                100 parts 100 parts                                      10% oxalic acid in water                                                                            10 parts  10 parts                                      ______________________________________                                    

Pieces of glass fabric, 4.5 oz. per square yard Beta casement fabric,were impregnated with either bath C or bath D, squeezed with a rollerand dried in air, followed by placing in a 100° C oven for 10 minutes.The fabrics weight increased by 6.5%. Strips of 2×12 inches were cut forflammability tests after conditioning for 24 hours at 76° F and 85%relative humidity. They were kept in a vertical position and ignited by2 successive 3-second contacts with the flame of a Bunsen burner. Afterignition, samples treated with bath C burned the entire length; whereas,samples treated with bath D were difficult to ignite andself-extinguished after removal of the burner flame.

Although specific materials and conditions were set forth in the aboveexemplary processes in making and using the fire retardant polymers andblends of the present invention, these are merely intended asillustrations of the present invention. Various other reactants,conditions, additives and ordinarily flammable polymers such as thoselisted above may be substituted in the examples with similar results.

Other modifications of the present invention will occur to those skilledin the art upon a reading of the present disclosure. These are intendedto be included within the scope of this invention.

What is claimed is:
 1. An aqueous emulsion comprising particles of anemulsion polymer consisting essentially of:1. from about 10 to 98% byweight of a vinyl or vinylidene halide;
 2. from about 1% to 89% byweight of at least one bis(hydrocarbyl)vinyl phosphonate having thestructure: ##STR5## wherein X is selected from the group consisting ofhydrogen, halogen, cyano, aryl, C₁ -C₁₈ alkyl and ##STR6## wherein R andR' are hydrocarbyl and substituted hydrocarbyl groups which can be thesame, different or conjoint; and
 3. from about 1% to 45% by weight of atleast one third comonomer selected from the ethylenically unsaturateddicarboxylic acids, anhydrides and the C₁ -C₂₀ mono- and dialkyl estersthereof.
 2. An aqueous emulsion as defined in claim 1 wherein the halideis vinylidene chloride.
 3. An aqueous emulsion as defined in claim 1wherein the third comonomer is selected from the group consisting ofaconitic acid, fumaric acid, maleic acid, itaconic acid, citraconicacid, maleic anhydride, dibutyl fumerate, di-n-octyl fumarate, andmonoethyl maleate.
 4. An aqueous emulsion as defined in claim 1 whereinthe bis(hydrocarbyl)vinyl phosphonate is bis(beta halo lower alkyl)vinylphosphonate.
 5. An aqueous emulsion as defined in claim 4 wherein thebis(beta haloalkyl)vinyl phosphonate is bis(beta chloroethyl) vinylphosphonate.
 6. An aqueous emulsion as defined in claim 1 wherein theemulsion polymer consists essentially of vinylidene chloride, di-n-butylvinyl phosphonate, and a di-n-octyl fumarate.
 7. An aqueous emulsion asclaimed in claim 1 wherein the emulsion polymer consists essentially ofabout 65% by weight vinylidene chloride, about 15% by weight ofdi-n-butyl vinyl phosphonate and about 20% by weight of di-n-octylfumarate.
 8. An aqueous emulsion comprising particles of an emulsionpolymer consisting essentially of:1. from about 10 to 98% by weight of avinyl or vinylidene halide;
 2. from about 1% to 89% by weight of atleast one bis(hydrocarbyl)vinylphosphonate having the structure:##STR7## wherein X is selected from the group consisting of hydrogen,halogen, cyano, aryl, C₁ -C₁₈ alkyl and ##STR8## wherein R and R' arehydrocarbyl and substituted hydrocarbyl groups which can be the same,different or conjoint;
 3. from about 1% to 45% by weight of at least onethird comonomer selected from the ethylenically unsaturated dicarboxylicacids, anhydrides and the C₁ -C₂₀ mono- and dialkyl esters thereof;and4. from 1% to 5% of N-methylol acrylamide.